1. Field of the Invention
This invention relates to an improved patch for repair or finishing a surface, such as a dry wall or plaster surface as would be found in walls and ceilings.
2. Description of the Prior Art
Many different techniques have been described in the prior art for repairing defects such as holes, cracks and indentations in walls and ceilings. Typically, walls and ceilings are made of plaster or dry wall material, often referred to as sheetrock. Sheetrock is a material made of Plaster of Paris or the like that is sandwiched between cardboard inner and outer surfaces.
The usual method of repair is to first fill the hole with a backing material such as newspaper, wire mesh, etc. and then to apply a patching compound. This method is difficult since the backing material often moves and, even if it is stationary, a weak spot remains in the wall.
In a finish operation, such as that required to cover the space between two sheets of sheet rock, joint compound is applied over the joint and dry wall tape is pressed into the joint compound. After this, multiple applications of joint compound or spackle are applied over the dry wall tape in order to provide a smooth and tapered surface to the surrounding wall. This is a process which takes several days, since multiple layers of joint compound are required and because a certain amount of drying time must be allowed between applications of the different layers.
In the prior art, various types of patches have been described to more easily effect repair of broken surfaces in walls and ceilings. Most of these patches utilize a center portion intended to cover the hole or crack in the wall and an outer portion which is thinner than the center portion. This allows the patch to be tapered in order to provide a smooth transition between the patch covering the imperfection and the surrounding wall. Typically, the patch is adhered to the wall by application of glue, joint compound or spackling paste and the like, after which an additional coat of joint compound is applied to provide a smooth tapered surface between the patch and the surrounding wall. Examples of these prior art patches include those described in U.S. Pat. No. 4,776,906 (a heat-shrinkable film designed to provide a wrinkle-free patch);
U.S. Pat. No. 4,135,017 (a laminate patch employing a plate in the center of the patch and a plate cover thereover); or U.S. Pat. No. 4,959,251 (an elastic patch); U.S. Pat. No. 4,122,222 (a preformed laminate having plaster or a spackling material in the center portion); or U.S. Pat. No. 4,398,495 (a laminate structure including dry wall papers held together by hardened joint compound). In order to use these laminates, they are first adhered to the wall or ceiling by the use of joint compound or glue. This creates an additional step requiring more time to effect the repair even though an improvement is provided over the traditional approach using a backing material inserted into the hole. Further, for surfaces that are not perfectly planar, the use of a rigid patch is limited.
The patch of U.S. Pat. No. 4,358,495 is intended to somewhat accommodate irregularities in the surface. This is accomplished by dipping the patch in water to make the dry wall papers flexible. However, only the dry wall papers become flexible. The hardened joint compound stays hard even when wetted. Further, this patch must be adhered to the wall surface using joint compound or a similar material which is an additional step. In this patch, the presence of hardened joint compound between the layers of dry wall paper is intended to provide a localized rigid backing material, and therefore serves a function similar to that provided by the aluminum sheet of U.S. Pat. No. 4,135,017.
The various patches described in the prior art, although providing advantages, all have features that are disadvantageous. These patches require joint compound or glue for initial attachment to the wall or ceiling surface, and are typically more costly laminate structures. Further, since they are laminates including multiple sheets of material, it is possible to have delamination or shifting of the laminate layers with respect to one another.
Accordingly, it is an object of the present invention to provide an improved patch for dry wall and plaster surfaces and method of use thereof, which can be adhered to a wall or ceiling without an additional coating of glue, joint compound or other similar material.
It is another object of this invention to provide an improved patch for dry walls and plaster surfaces which is inexpensive and easy to use.
It is another object of this invention to provide an improved patch and method for repairing imperfections in dry wall or plaster surfaces, or for finishing these surfaces.
It is another object of this invention to provide an improved patch for repair or finishing of wall or ceiling surfaces, which can be used on planar surfaces as well as non-planar surfaces, including inside and outside corners.
It is another object of this invention to provide an improved patch and method for repairing or finishing walls or ceilings in which the patch can be easily stored for later use.